Today has already been described as the most important day in publishing history since Johannes Gutenberg thought of movable blocks of metal with letters on them, which makes it a big day for the Blair-hating community. For an alarming proportion of my colleagues in journalism and allied trades, the idea that Tony Blair's memoir might provide an important and instructive account of how one of the most successful of modern British prime ministers saw his time in office is simply preposterous. The main lines of inquiry can be sketched out now: Does he apologise for Iraq? Does he admit he was a shallow chancer whose only achievement was to introduce the word spin to the English language? And so on, for thousands and thousands of words. All day.
Immoderate views of Blair are held by a minority of the population, while in the media class they are the norm. The notion that Blair was, on balance, quite a good prime minister, is often regarded as an extremist statement. The BBC in particular seems to regard "on balance a good thing" and "war criminal" as moral equivalents of equal weight, and the airing of both as fulfilling its obligation under Royal Charter to impartiality. And this daft idea of balance is made easy not just by the world-view of most BBC journalists but by the easy availability of so-called serious commentators who hold views about Blair – "evil" is an interesting word, used by Matthew Parris on the right and Natasha Walter on the left – that seem to me to be detached from reality. So where does such incontinent Blair rage come from?
I have been puzzling over this for some time and, amid all the bile and insults my inquiry provokes, the response of one Blair hater was useful: "You well know that many people believe he deceived Parliament and this country into an unnecessary war. Given that is what people believe, then the anger is easy to understand isn't it?"
Up to a point, but this only takes the question back one stage: back to why so many people believe such an unreasonable and unlikely thing. And it usually turns out that they don't. Very few people actually believe that Blair had a meeting – on a sofa in Downing Street, naturally – and said to his closest advisers: "I've got this brilliant plan for joining the American invasion of Iraq: we'll say it's all about weapons of mass destruction and when it turns out that there aren't any, everyone will hate me for ever. How does that sound?" Great plan, they all said, and made the necessary preparations.
What people believe is not that Blair lied, but that he was so desperate to keep in with the Americans that he exaggerated the threat from Saddam Hussein. That has the advantage of fitting with what was the conventional view, that the British interest is best served by a close alliance with the US, but overlooks the more obvious reason for assuming the worst of Saddam, namely his previous history of concealment.
Variants of Blair-hating belief are endless; the one that is most pleased with itself being the Clare Short Interpretation, that Blair was so eager to please George Bush that he deceived himself. Well, it's a theory, isn't it? But how does it explain or justify hatred, or the word "evil"? The emotions it might evoke could be pity, or disdain, and the adjective could be weak or deluded. But the anger inspired by Blair suggests that something else is at work.
I think what happened is that the case for use of military force against Saddam was the dominant view of the political-media establishment. It was supported – for all the good reasons that were given at the time – by the leaderships of the two main political parties, most of the newspapers (this one and its Sunday sister notably excluded) and in Whitehall. There was a strongly held opposing view, which mobilised a large demo on the eve of the invasion, and public opinion remained sceptical, although it swung behind the policy once troops were deployed. There were only two important resignations as the decision was taken, one political (Robin Cook) and one official (Elizabeth Wilmshurst).
Then, when the weapons of mass destruction could not be found, there was a big gap to be explained. Historians might explain it by Saddam's practising his last and worst-calculated deception, wanting the Iranians and his own apparatchiks to believe that he had the weapons; by US-British intelligence experiencing the phenomenon of groupthink; and by the military overconfidence generated by Kosovo and Afghanistan. But those explanations did not fill the psychic hole in the here and now – so people preferred to say that they had been deceived than that they shared a mistaken assumption.
That idea of deception is where the poison starts. I don't know why we rarely hear from people who accept that Blair, Cabinet, Parliament and civil servants thought that they were acting in the national interest but miscalculated. But no, we get the most strident commentaries and Socialist Workers Party slogans about lies. From there the idea of deception spreads to contaminate the Labour left, who never forgave Blair for winning elections, and to the Daily Mail right, who never forgave him for winning elections. It feeds the conspiracy theories about David Kelly (who supported military action against Iraq but whose ghost has been co-opted by its opponents). Nothing Blair can say in his book today can stop the flow; the anger against him exists at a deeper level, impervious to reasoned argument, certainly from him.
But it is interesting that, outside the compound of self-reinforcing London liberal media opinion, there is a more balanced assessment of Blair. A survey of 100 academics specialising in politics or history published last month ranked him third among postwar British prime ministers, behind Clement Attlee and Margaret Thatcher. Professor Kevin Theakston, who compiled the survey, noted mildly that Blair was the second-longest serving prime minister of the period. The poison has not gone too deep, then. But perhaps it is too much to hope that enough people will read the book with enough of an open mind to begin to turn the tide of media bile.
John Rentoul is chief political commentator for 'The Independent on Sunday' and biographer of Tony Blair